'03 LS8 Fan Failure

Hey guys, my LS decided to heat creep in my work parking lot this morning while idling. Pissed off, I got out of the car to find that The cooling fan/radiator isn't working at all. Didn't have time to check it out.

I was under the impression that the2nd gen fans are electric and don't fail like the 1st gen Hydro fans. But Anyhow, where is The fuse/relay for my fan located? I'm praying that it's just a bad fuse or something.

From the owner's manual:"In-line fuse for electric cooling fan There is a 60A maxi fuse for the electric cooling fan located in a wiring harness behind the front passenger side trim panel under the dash panel. The trim panel must be removed and the carpet on the front passenger side must be lifted to access this fuse. See a qualified technician to have this fuse replaced, if necessary."

2nd gen electric fan failure is rare, but is not unheard of. Do a search, as there are some threads (one recent) on troubleshooting the 2nd gen electric fan.

I found this, does this v6 troubleshooting procedure apply to my 03 v8?

If this series of tests apply to my cooling fan as well, what do I need to go buy to do the tests? A volt meter? What do you use to check for battery power to the wire etc.? Also, what do you use to jump the green/yellow wire?

Yes, it's the same for the V8 or the V6. Get a reasonable multi-meter. Don't cut the wire insulation, unplug the connectors to check for power. Plug the big one back in and then jumper power to the pin of the green/yellow wire to test for fan operation.

Yes, it's the same for the V8 or the V6. Get a reasonable multi-meter. Don't cut the wire insulation, unplug the connectors to check for power. Plug the big one back in and then jumper power to the pin of the green/yellow wire to test for fan operation.

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Okay I'm going to go buy a meter from AutoZone. So I unplug the connector containing the larger wires, and check the pin inside the connector that corresponds with the green/orange wire? And assuming it has power (which would verify the 60a inline fuse is good), I plug the connector back into fan assembly.

How do I jumper power to the green/yellow wire?

I have two sets of two wires. The bigger ones contain a orange wire with green stripe (power I believe), and a black wire (ground I believe). The smaller ones contain a white wire with green stripe, and a white wire with blue stripe. According to the past hour of research, I believe one of these is connected to a sensor/switch that reads a signal that determines fan speed. And the other wire is an activation switch or something.

Regardless, according to the wires I've described, could you please tell me how to do this jumper process in detail. Sorry I'm a pain in the ass, just don't want to mess anything up and want to make sure I do it right so my results are correct.

The large connector is the fan power connector (60A fuse). Disconnect and check for 12V power. It'll be there key on or key off. Then reconnect that one. Don't jumper to the big one!

Now disconnect the little one. The green/white wire should have +12V when the key is on. If so, then jumper between the green/white wires on each side of the connector, leaving the other wire unjumpered. If the fan is good, it will come on at high speed.

If this is still unclear, (you had the connectors backwards a moment ago), then don't do it. Remember, no jumpering to the big connector, ever.

The large connector is the fan power connector (60A fuse). Disconnect and check for 12V power. It'll be there key on or key off. Then reconnect that one. Don't jumper to the big one!

Now disconnect the little one. The green/white wire should have +12V when the key is on. If so, then jumper between the green/white wires on each side of the connector, leaving the other wire unjumpered. If the fan is good, it will come on at high speed.

If this is still unclear, (you had the connectors backwards a moment ago), then don't do it. Remember, no jumpering to the big connector, ever.

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I bought this, have no idea how to use it. I'd assume I set it to the "12v" battery setting correct? Not quite certain which terminals to connect the wire posts to though.

But ultimately let me get this straight. You say to jumper the green/white small wire between connectors correct? So do I just link some wire between the harness clip terminal and the corresponding terminal on the fan assy? And that's all?

Ultimately resulting in the white/blue striped wire being the only wire left out. Is this correct?

... But ultimately let me get this straight. You say to jumper the green/white small wire between connectors correct? So do I just link some wire between the harness clip terminal and the corresponding terminal on the fan assy? And that's all?

Ultimately resulting in the white/blue striped wire being the only wire left out. Is this correct?

The fan on my '03 failed about 6 years ago, so they do fail. Just like most things LS, changing the fan is harder than it should be. It's some sort of variable speed fan, but if it has power and ground, it should run. I paid $375 for mine when i bought it, and I'm sure it'll cost more now.

The fan in my 06 is currently failed. A new one from Ford is about $1000. I have the less common 4 wire single connector type, and am having trouble finding one used.

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You could convert a duel connector fan to the single four wire one. Just cut the wires to the two connectors off the used fan and splice in the single four wire connector from your failed fan. Alternately, you could change the connector on your LS, if you could get the two connected from an LS in the junk yard.

I have 12v power at the Main Power Wire (Whew, no blown fuse). And I have +12v power on the Green/Yellow wire when the key is turned on.

I Plugged the Power/Ground harness clip in, and jumped the Green/Yellow wire. And all of a sudden Chicago Oaire International Airport is in my garage. Sounds like a damn airplane turbine.

I don't know if this is good news or bad. Because judging by your (Joegr) last post on the other guys v6 fan thread, I still have an issue. If the fan doesn't work when jumped, the fan is crap. If the fan DOES work, the PCM is bad.

For some reason I have a feeling I wish my fan was crap, because PCM just sounds expensive as hell and dealer only.

So here is my series of questions...

If I don't mind the fan being on high speed all the time (Whenever the key is on), and I decide to solder it for a temporary fix, would this hurt anything? I mean... I'd assume the fan is only intended to be on "high" for intermittent sessions of the Engine being warm and/or hot. So I suppose I could see this shortening the life of the fan, but would it likely burn up the fan motor?

Also, if there is nothing dangerous or wrong with me rigging up my fan to be ran on high all the time...

Is there anything restricting me from purchasing a universal fan? I mean, if I did some searching and found one that would be in decent dimension of clearance from the engine serpentine belt and the stock intakes lower shroud (Massive pointless plastic waste of space in front of cooling fan) And I took the time to make a custom secure mount for it... Is there any reason I couldn't use my current wiring harness that contains Power, Ground, and a +12v ignition switch?

I suppose what I'm trying to say is, what would you do? How much is a PCM and what am I looking at?

But ultimately what I need answered is... is there anything wrong with my current factory fan being switched to high at all times?

Thanks as always LVC, and especially you Joe. At least I know where I stand with the issue now, and I didn't electricute the s*** out of myself.

Well I'm off to church in the Fusion with my wife... what a joy to drive -.-

I would suspect that having the fan on high all the time would cause early alternator failure. I think that used PCMs are in the $500 range. New PCMs for the 2006 are in the $700 to $900 range. For the 2003, they are listed as out of production/stock.

I would reconnect the fan and hook up a good scan tool and look at live sensor values to try and see why the PCM is not running the fan. Maybe it's a temperature sensor and not the PCM. The KOEO self test should also briefly start the fan.

I would suspect that having the fan on high all the time would cause early alternator failure. I think that used PCMs are in the $500 range. New PCMs for the 2006 are in the $700 to $900 range. For the 2003, they are listed as out of production/stock.

I would reconnect the fan and hook up a good scan tool and look at live sensor values to try and see why the PCM is not running the fan. Maybe it's a temperature sensor and not the PCM. The KOEO self test should also briefly start the fan.

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Are there any temperature sensors in the vicinity of the area I worked on to do my cooling system overhaul last August? I could inspect those for power failure etc.

I don't have the money to invest $200 on a good scan tool and additional $250 for Ford software.

Would it be advisable for me to reconnect the fan, and just take it to the Ford dealer and have them diagnose it? Or is that probably just a waste of my money?

Also, would there be anything against me purchasing a universal one speed fan that would operate at less rate and use less voltage/amps? Because I wouldn't mind fabricating a mount and going aftermarket. Comments?

Well.. Granted many of you will call me an idiot, I've went my own route with this one. Me and my wife currently don't have the funds to have the car dealer diagnosed and aren't prepared to purchase a new PCM etc. I'm well aware that the choice I made could likely bite me, and bite hard. But I'm going by faith here.

I basically spent the entire afternoon installing a huge jumper wire. However, with the knowledge of the fan running all the time being potentially hazardous to my alternator, I've installed a switch.

The way I see it, the car never really needs the fan except when it's hot and your not driving fast or consistent enough to provide the engine with air. With this switch, I can temporarily provide serious air flow in heavy traffic, and often slow/stopped driving conditions.

I want to eventually get this fixed properly, but at the moment... A $25 investment in 16g wire, a switch, wire loom, and some carb cleaner had to do.(Cleaned my throttle body while intake was removed, it was actually quite disgusting)

Well that's all for now, all I can do is pray it continues to function well. God bless you all, good night.

A switch is good, but I hope you also included a fuse in your jury-rigged system. Always put in a fuse.

Your local dealer should charge an hour's shop time for a diagnostic. In the Tulsa area, that's 80 bucks or so. Hopefully, you wired that up so that you can just plug the factory wiring back in which would make it very easy for you to drive it to the dealer as-is, then unplug your jury-rigging and plug in the factory wiring so they can test it.

I believe that my fan failed because I had an overheating problem for a while. I drove around for months with the fan on high all the time. The car was not really overheating, but the temp was above the set amount and the computer ran the fan at high after the engine warmed up. Good luck with your manual fan control setup. My car is fine without the fan except that the AC does not work when stopped, and temp will start creeping up after 5-10 min of idle.

I would worry that the PCM may not know how hot the engine is running, since it's not turning the fan up when it needs to. If so, then the PCM will also not go into failsafe cooling when there is a problem. It could let you toast the engine without you or it knowing it, till it is too late. It may also use the wrong fuel and timing strategy. I fear you may be going for a false economy that could cost you big time.